Ni(HO)2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-625074 · Space group: C2 (#5)

Materials Project API

Basic Information

Formula

Ni(HO)2

MP-ID

mp-625074

Elements

Sites

Density

3.7785

g/cm³

Volume

40.74

Å³

Cell a

3.1625

Cell b

3.1625

Cell c

4.7322

α Angle

84.36

β Angle

84.36

γ Angle

60.05

Space Group

Point Group

Crystal System

Monoclinic

Bravais Lattice

Stability

Packing Fraction

X-ray Diffraction

Diffraction Pattern

Target / Radiation

X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å

Diffraction Peaks (Top 24)

2θ	d (Å)	I	hkl
18.87	4.7016	100.0	(0,0,1)
32.74	2.7357	27.7	(1,0,0)
32.92	2.7205	7.5	(1,1,0)
36.22	2.4799	28.4	(1,1,1)
37.06	2.4255	7.7	(1,0,1)
38.29	2.3508	4.6	(0,0,2)
39.03	2.3080	55.9	(1,0,-1)
40.14	2.2467	4.6	(1,1,-1)
48.20	1.8879	14.0	(1,1,2)
49.67	1.8355	12.9	(1,0,2)
52.77	1.7347	17.8	(1,0,-2)
54.40	1.6865	6.6	(1,1,-2)
58.31	1.5824	8.1	(1,-1,0)
58.67	1.5736	14.9	(2,1,0)
58.93	1.5672	2.1	(0,0,3)
60.14	1.5385	10.7	(2,1,1)
61.87	1.4998	7.2	(1,-1,1)
64.24	1.4499	4.4	(2,1,-1)
65.25	1.4300	2.5	(1,1,3)
67.12	1.3946	9.1	(1,0,3)
68.40	1.3716	2.5	(2,1,2)
68.61	1.3679	2.2	(2,0,0)
69.05	1.3602	2.3	(2,2,0)
70.61	1.3340	6.2	(2,0,1)

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Energy Properties

Formation Energy/atom

-1.23614

eV/atom

Energy/atom

-5.72942

eV/atom

Energy above Hull

0.0191

eV/atom

Uncorrected Energy

-4.9464

eV/atom

Volume/atom

8.15

Å³

c/a Ratio

1.4963

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

2.0004

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.049100

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

H · 0.400

Element Family

Alkali-AlkEarth

Solute Fraction

0.600

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0549

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.7706

J/mol·K

Ω Parameter

0.0000

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

61.502%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.6633

smaller = more stable mixing

VEC

4.000

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

0.000

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9602

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.402

Family

H-rich Multi-Component

Matrix Element

H · 0.400

Related Tasks

Related computation task IDs (7)

aaaclsep aaaclseq aaadnvlv aaadtkpk aaadydqu aaaetgfn aaafsnum

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-625074

Reference Citation

The crystal structure and related material properties of Ni(HO)2 were obtained from the Materials Project database (MP-ID: mp-625074, database version v2026.04.13).

Literature Citation

Horton, M.K., Huck, P., Yang, R.X. et al. Accelerated data-driven materials science with the Materials Project. Nat. Mater. 24, 1522–1532 (2025). https://doi.org/10.1038/s41563-025-02272-0

3D Crystal Structure Rendering

Loading 3D structure…

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Raw CIF Data

# generated using pymatgen
data_Ni(HO)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.16252198
_cell_length_b   3.16252198
_cell_length_c   4.73215033
_cell_angle_alpha   84.35951931
_cell_angle_beta   84.35951931
_cell_angle_gamma   60.04870785
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ni(HO)2
_chemical_formula_sum   'Ni1 H2 O2'
_cell_volume   40.74297706
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ni  Ni0  1  0.04846000  0.95154000  0.00000000  1.0
  H  H1  1  0.78020800  0.60914000  0.57932700  1.0
  H  H2  1  0.39086000  0.21979200  0.42067300  1.0
  O  O3  1  0.73839300  0.64096900  0.78342300  1.0
  O  O4  1  0.35903100  0.26160700  0.21657700  1.0

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